Rope tensioning apparatus



June 20, 1967 P. MAczuzAK lROPE TENSIONING APPARATUS 2 Sheets-Sheet l Filed Oct. l5, 1965 June 20, 1967 p MACZUZAK 3,326,356

ROPE TENSIONING APPARATUS Filed oct. 15, 1965 2 sneets-sneei 2 INVENTOR. PETER MGZUZK United States Patent O 3,326,356 ROPE TENSIONING APPARATUS Peter Macznzak, Ellsworth, Pa., assigner to Lee-Norse Company, Charleroi, Pa., a corporation of Delaware Filed Oct. 15, 1965, Ser. No. '496,309 9 Claims. (Cl. 198-208) This invention relates to an apparatus for equalizing the tensions in a plurality of rope strands and more speciiically to the provision of a new and improved appara- 4tus of this type which is particularly adapted for equalizing the tensions in the rope strands supporting the c-onveyor belt of a conveyor.

Conventionally, an extendible conveyor is usually provided with a plurality of rope strands which cooperate to support the conveyor belt intermediate the head and tail sections of the conveyor when the conveyor is in an extended position. The rope strands are generally connected to the head and tail sections of the conveyor to be adjusted in effective length during the extension and retraction of the conveyor and are necess-arily maintained un- -der tension throughout their adjustment in length.

The tension in each one of the rope strands of these conventional extendible conveyors, however, is usually substantially independent of the tension in the yother of the rope strands. Thus, in the operation of these conventional conveyors a differential has frequently occurred between the tensions in the rope strands. This tension differential has commonly caused the rope strands to provide uneven support for the conveyor belt and to permit lateral slippage of the conveyor belt.

An object of the present invention is to provide a new and improved apparatus which is automatically responsive to a differential between the tensions in the rope strands to immediately equalize the tensions in the lrope strands and Ithereby prevent this uneven support and slippage of the conveyor belt which commonly occurs in conventional extendible conveyors.

Another object of the invention is to provide a new and improved apparatus of the type set forth which is relatively simple land economical in construction and highly efficient in operation.

These objects, and those other objects and advantages of the invention which will be apparent from the following description taken in connection with the accompanying drawings, are accomplished by providing a connecting member disposed intermediate the rope strands, and means carried by the connecting member for connecting the rope strands to the connecting member to subject the latter to the tensions in the rope strands and make the connecting member move to balance the tensions in the rope strands at an equalized value in response to a tension differential between the rope strands. j

Referring to the drawings wherein the preferred forms of the invention have been given by way of illustration only:

FIG. 1 lis a partial elevational view of an extendible conveyor including an apparatus which is an embodiment of the present invention; l

FIG. lA is a partial elevational view of the extendible conveyor showing the portion thereof extending beyond line A-A of FIG. 1;

FIG. 2 is an enlarged fragmentary longitudinal view illustrating the details of construction of the embodiment -of the present invention which is on the extendible conveyor show-n in FIGS. 1 and 1A;

FIG. 3 is a fragmentary elevational view of the appa-ratus illustrated in FIG. 2 taken on line 3--3 of FIG. 2, looking in the direction of the arrows;

FIG. 4 is an enlarged, fragmentary longitudinal view of a modified embodiment of the present invention; and

Patented June 20, 1967 lCe FIG. 5 is a sectional view `of the apparatus illustrated in FIG. 4 taken on line 5 5 of FIG. 4, lookin-g in the direction of the arrows.

Referring more particularly to the drawings wherein similar reference characters designate correspondi-ng parts throughout the several views, FIGS. v1 and 1A, taken together, illustrate an extendible conveyor ydesi-gnated genorally :at which is in an extended position. The extendible conveyor 10 is of the type disclosed in application Ser. No. 411,907, which was filed on Nov. 17, 1964,

v by George Baechli and is assigned to the assignee of the present invention.

The extendible conveyor 10 comprises a supporting frame having a head section 12 and a tail section 14. The head section 12 is supported and longitudinally movable by a plurality of crawlers 16 and pivotally carries a loading hopper 18 at its head en-d. The tail section 14 is detachably securable upon the tail end of the head section 12 for longitudinal movement with the head section 12 and is adapted to be fixedly supported by a plurality of anchor jacks\20 upon detachment from the head section 12.

An endless conveyor belt 22 longitudinally connects the head section 12 with the tail -section 14 and extends into the loading hopper 18. The conveyor belt 22 is longitudinally movable relative to the head section 12, the tail section 14, and the loadin-g hopper 18 to convey material deposited in the loading hopper 18 to the tail section 14. The conveyor belt 22 is automatically extendible and retractable in effective length upon longitudinal movement of the head section 12 relative to the tail section 14 by a belt storage apparatus (not shown) carried by the head section 12. The conveyor belt 22 is supported intermediate the head section 12 and the tail section '14 by a plurality of manually located supporting stands 24 when the extendible conveyor 10 is in an extended position. The supporting stands 24 are maintained in an upright or vertical position by the substantially parallel rope strands or runs 26 and 28 which extend longitudinally along the opposing sides of the conveyor belt 22.

As illustrated in FIG. 2, the rope strand 26 is secured at one of its ends to the tail section 14 and is wound at the other of its ends upon a rope drum 30 which is located adjacent one si-de of the head section 12. The rope strand 28 similarly is secured at one of its ends to the tail section 14 and is wound at the other of its ends upon a rope drum 32 which is located adjacent the opposing side of the head section 12 from the rope drum 30. The rope drums 30 and 32 are carried by a single rotatable shaft 34 for rotation therewith, the shaft 34 being rotatably 'driven by a drive motor 33 through a driving chain 35. Thus, the rope strands 26 and 28 are adjustable in effective length as necessitated by the extension and retraction of the extendible conveyor 10 and are maintained under tension throughout their adjustments in effective length.

The present invention comprises the provision of an apparatus which employs a differential between the tensions in the rope strands 26 and 28 to balance the tensions in such rope strands at an equalized value. Due to this employment of a tension differential as the balancing agent, the apparatus is substantially immediately responsive to a difference between the tensions in the rope strands 26 and 28 to automatically equalize such tensions.

This apparatus, as illustrated in FIGS. 2 and 3, comprises a connecting member 36 which is slidably disposed upon the head section 12 intermediate the rope strands 26 and 2S. The connecting member 36 extends substantially normal to the rope strands 26 and 28 and includes an end portion 36a adjacent the rope strand 26 and an end portion 36b adjacent the rope strand 28. The end portion 36a of the connecting member 36 carries a irst rope sheave 38; the end portion 36b of the connecting member 36 carries a second rope sheave 40.

The rope strand 26 is passedv or looped around the first rope sheave 38 such that the tension in the rope strand 26 exerts a pulling force upon the connecting member 36. The rope strand 28 is passed or looped around the second rope sheave 40 such that the tension in the rope strand 28 exerts an opposing pulling force upon the connecting member 36. Thus, upon the occurrence of a differential between the tensions in the rope strand 26 and 28, the opposing forces exerted by such tensions on the connecting member 36 automatically and substantially immediately relocate the connecting member 36 to balance such tensions at an equalized value. This use of the tension differential as the balancing agent, as will be seen, causes the resultant, equalized tension in the rope strands 26, 28 to attain a value intermediate the values of the unbalanced tensions previously in the rope strands 26, 28.

The head section 12 carries a guiding means for limiting the slidable movement of the connecting member 36 to a direction substantially normal to the rope strands 26 and 28. This guiding means comprises a first pair of retaining rope sheaves 42 and 44 which receive the rope strand 26 upon the opposing sides of the connecting memiber 36 and a second pair of retaining rope sheaves 46 and 48 which receive the rope strand 28 upon the opposing sides of the connecting member 36. The retaining sheaves 42, 44, and 46, 48 restrict the locations at which their respectively received rope strands 26 and 28 extend towards the connecting member 36 to thereby limit the direction ofthe slidable movement of the connecting member 36;

In the operation of the beforedescribed apparatus, the connecting member 36 is normally initially located midway between the rope strands 26 and 28. The connecting member 36 retains this location as long as the rope strands 26 and -28 remain under equal tensions. When, however, the tension in one of the rope strands 26 and 28 exceeds that of the other of such rope strands, the greater tension in the one of the rope strands draws the connecting member 36 towards such rope strand until the tensions arel again equalized at a balanced value. Thus, assuming the rope strand 28 to have -a greater tension than the rope strand 26, the connecting member 36 will be moved from its solid position of FIG. 2 to a position similar to its illusionary position therein. Similarly, lthe apparatus is responsive to further tension dilerentials to automatically and substantially immediately re-equalize the tensions in the rope strands 26 and 28.

FIGS. 4 and 5 illustrate a modified embodiment of the present invention. In this form of the invention, the head section 12 is provided with a guiding track 50 which extends normal to the rope strands 26 and 28. The connecting member 36 is slidably disposed within the guiding track 50 to be restricted thereby to movement normal to the rope strands 26 vand 28.

The loperation of this embodiment of the invention is believed to be apparent from the foregoing description.

From the foregoing, it will be seen that I have provided a new and improved apparatus for accomplishing al1 of the objects and advantages of my invention.

Having thus described my invention, I claim:

1. In combination with a conveyor having a supporting frame including a head section and a tail section, an endless conveyor belt longitudinally connecting said head and tail sections, and a pair of spaced rope strands under tension extending between said head and tail sections for supporting said conveyor bel-t therebetween, an apparatus for automatically equalizing the tensions in said rope v strands, comprising:

means carried by said connecting member for connecting said rope strands to said connecting member to subject the latter to the tensions in said rope strands and make said connecting member move, in response to a tension differential between said rope strands, to balance the tensions in said rope strands at an equalized value intermediate the differential tensions therein.

2. In combination with a conveyor having a supporting frame including a head section and a tail section, an endless conveyor belt longitudinally connecting said head and tail sections, and a pair of spaced rope strands under tension extending between said head and tail sections for supporting said endless conveyor belt therebetween, an apparatus for automatically equalizing the tensions in said rope strands, comprising:

a connecting member disposed intermediate said rope strands for movement towards each of said rope strands; and

means carried by said connecting member for connecting said rope strands, intermediate their ends and in opposing relationship, to said connecting member such that, upon the occurrence of a tension differential between said rope strands, the rope strand having the higher tension draws said connecting member towards the latter mentioned rope strand to cause the tensions in said rope strands to be equalized at a value intermediate the differential tensions.

3. A tension equalizing apparatus according to claim 2, wherein a guide means is provided for restricting said connecting member from movement other than towards one of said rope strands.

4. In combination with a conveyor having a supporting frame including a head section and a tail section, an endless conveyor belt longitudinally connecting said head and tail sections, and a pair of spaced rope strands under tension extending between said head and tail sections for supporting said endless conveyor belt therebetween, an apparatus for automatically equalizing the tensions in said rope strands, comprising:

a connecting member disposed intermediate said rope strands for movement towards each of said rope strands and having an end portion extending towards each of said rope strands; and

means carried by said connecting member for connecting each of said rope strands intermediate its ends to the respective adjacent end portion of said connecting member such that, upon the occurrence of a tension differential between said rope strands, the rope strand having the higher tension draws said connecting member towards the latter mentioned rope strand to cause the tensions in said rope strands to be equalized at a value intermediate the diierential tensions.

5. A tension equalizing apparatus according to claim 4, wherein a guide means cooperates with one of said connecting member and said rope strands to restrict said connecting member from movement other than towards one of said rope strands.

6. In combination with a conveyor having a supporting frame including a head section and a tail section, an endless conveyor belt longitudinally connecting said head and tail sections, and a pair of spaced rope strands under tension extending between said head and tail sections for supporting an endless conveyor belt therebetween, an apparatus for automatically equalizing the tensions in said rope strands, comprising:

a connecting member disposed intermediate said rope strands for movement towards each of said rope strands and having an end portion extending towards each of said rope strands; and

a sheave carried by each of said end portions of said connecting member for receiving the respective adjacent rope strand and connecting such intermediate its ends to said connecting member such that, upon the occurrence of a tension differential between said rope strands, the rope strand having the higher tension draws said connecting member towards the latter mentioned rope strand to cause the tensions in said rope strands to be equalized at a value intermediate the differential tensions.

7. A tension equalizing apparatus according to claim 6, wherein track means cooperate with said connecting member to restrict movement of said connecting member other than towards one of said rope strands.

8. A tension equalizing apparatus according to claim 6, wherein a plurality of second rope sheaves cooperate with said rope strands to restrict movement of said connecting member, other than towards one of said rope strands.

References Cited UNITED STATES PATENTS 5/1906 Adam 198-208 X EVON C. BLUNK, Primary Examiner.

A. C. HODGSON, Assistant Examiner. 

1. IN COMBINATION WITH A CONVEYOR HAVING A SUPPORTING FRAME INCLUDING A HEAD SECTION AND A TAIL SECTION, AN ENDLESS CONVEYOR BELT LONGITUDINALLY CONNECTING SAID HEAD AND TAIL SECTIONS, AND A PAIR OF SPACED ROPE STRANDS UNDER TENSION EXTENDING BETWEEN SAID HEAD AND TAIL SECTIONS FOR SUPPORTING SAID CONVEYOR BELT THEREBETWEEN, AN APPARATUS FOR AUTOMATICALLY EQUALIZING THE TENSIONS IN SAID ROPE STRANDS, COMPRISING: A CONNECTING MEMBER DISPOSED INTERMEDIATE SAID ROPE STRANDS FOR MOVEMENT RELATIVE TO SAID ROPE STRANDS; AND MEANS CARRIED BY SAID CONNECTING MEMBER FOR CONNECTING SAID ROPE STRANDS TO SAID CONNECTING MEMBER TO SUBJECT THE LATTER TO THE TENSIONS IN SAID ROPE STRANDS AND MAKE SAID CONNECTING MEMBER MOVE, IN RESPONSE TO A TENSION DIFFERENTIAL BETWEEN SAID ROPE STRANDS, TO BALANCE THE TENSIONS IN SAID ROPE STRANDS AT AN EQUALIZED VALUE INTERMEDIATE THE DIFFERENTIAL TENSIONS THEREIN. 